Protocol for the Derivation of Environmental and Human ... - CCME

Part A, Section 2
Section 2
National Protocol for the Derivation of Environmental and
Human Health Soil Quality Guidelines
2.1 What is the Protocol?
The protocol was developed by the SEQCCS to provide a method for replacing the Interim
Remediation Criteria for Soil with scientifically defensible guidelines for contaminated sites. Both
scientific and management considerations are necessary when deriving generic guidelines. The protocol
will provide stakeholders (i.e., public, industry, and regulatory agencies) with the basic concepts and
methods employed in guidelines development. The CCME is committed to document and present all
technical, scientific, and management considerations that are used to derive the guidelines.
The protocol focuses on soil because of the current lack of scientifically defensible guidelines in this
area. The protocol examines the steps needed to generate effects-based soil remediation guidelines
including a rationale for the choice of receptors, exposure pathways under certain land uses,
assumptions, and describes acceptable and minimum data required for guidelines derivation.
To protect the terrestrial ecosystem, the protocol derivation process considers the adverse effects from
exposure to soil-based contaminants at point-of-contact and indirect means (i.e., food chain transfer).
Potential exposure pathways, receptor arrays, and exposure scenarios are discussed for major land
uses. Based on these exposure scenarios, ecological receptors that sustain the primary activities for
each land-use category are identified.
To protect human health, derivation processes for threshold and non-threshold toxicants are
differentiated, taking into account background daily exposure from air, water, soil, food, and consumer
products. The protocol also identifies routes of potential indirect exposure, such as consuming
contaminated groundwater (at agricultural, residential and industrial properties), consuming
contaminated meat, milk, and produce (agricultural lands), consuming contaminated produce from
private gardens (residential property), infiltration into indoor air (residential property) and wind erosion
from industrial sites and deposition on neighbouring property. These indirect exposure routes are
evaluated conservatively by applying simplified transport and redistribution models using generic site
characteristics. These models protect or "screen" a wide variety of site conditions.
The guidelines are revised substance-by-substance after a comprehensive review of the
physical/chemical characteristics, background levels in Canadian soils, toxicity and environmental fate
and behaviour (see Figure 2). This background information will be published in a series of guideline
documents which summarize the human health and environmental information.
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